| Single LED flash, steadily on | This means your Goodman furnace has no signal coming from the thermostat and won't operate. | You should check your thermostat for an improper setting or connection. |
| Single LED flash, blinks on and off | This means that your furnace has locked out due to too many ignition attempts. | After one hour of lockout, your furnace will automatically reset itself. |
| Two LED flashes | This means that the draft blower isn't functioning properly, or your furnace has a short in the pressure switch circuit. | You should either repair the short or replace the pressure switch. |
| Three LED flashes | This means your furnace has an open pressure switch circuit or the induced draft blower is operating when it shouldn't be. | You should check the pressure switch hose for blocks or an improper connection. Otherwise, see if any loose wiring needs tightening. |
| Four LED flashes | This means your furnace has a primary open limit circuit. | You should check and clean all the filters, tighten the wiring, and see if there are any blockages in the flue. |
| Five LED flashes | This means that your furnace senses a flame without a call for heat. | You should check for a leaky or open gas valve or a lingering burner flame. |
| Seven LED flashes | This warns of a low flame sense microamp signal. This is the result of a coated flame sensor or a lazy flame due to poor gas pressure. | Adjust the gas pressure according to the information available to you. |
| Eight LED flashes | This means your furnace has an igniter circuit problem due to a defective igniter or an improperly connected igniter. | Replace the igniter or check the ground wiring for defects. |
| Nine LED flashes | This means that your furnace has a high-stage pressure switch that won't close during a high-stage-induced draft blower operation. | Check your Goodman furnace for a pinched or blocked pressure switch hose. |
| Continuous LED flashes | This means that your furnace has a reversed polarity of 115 volts. | You will have to correct the wiring polarity after reviewing the wiring diagram. |
